olymmath

DK-GEORGMOHR 2008

Georg Mohr Contest 2008.

Official paper

The official paper in 1 language

English

Other problems

Problem 1

Denmark has played an international football match against Georgia. the fight ended 5−55-5 , and between the first and the last goal the game has justnever stood . No country has scored three goals in a row, and Denmark scored the sixth goal. Can you use this information to determine which country scored the fifth goal?

Problem 2

If three integers p,qp, q and rr apply that p+q2=r2.p + q^2 = r ^2. Show that 66 adds up to pqrpqr .

Problem 3

The numbers from 11 to 500500 are written on the board. Two players AA and BB erase alternately one number at a time, and AA deletes the first number. If the sum of the last two number on the board is divisible by 33 , BB wins, otherwise AA wins. Which player can lay out a strategy that ensures this player's victory?

Problem 4

In triangle ABCABC we have AB=2,AC=6AB = 2, AC = 6 and ∠A=120o\angle A = 120^o . The bisector of angle AA intersects the side BC at the point DD . Determine the length of ADAD . The answer must be given as a fraction with integer numerator and denominator.